Evidence for a second regulatory binding site on PspF that is occupied by the C-terminal domain of PspA.

ABSTRACT: PspA is a key component of the bacterial Psp membrane-stress response system. The biochemical and functional characterization of PspA is impeded by its oligomerization and aggregation properties. It was recently possible to solve the coiled coil structure of a completely soluble PspA fragment, PspA(1-144), that associates with the σ54 enhancer binding protein PspF at its W56-loop and thereby down-regulates the Psp response. We now found that the C-terminal part of PspA, PspA(145-222), also interacts with PspF and inhibits its activity in the absence of full-length PspA. Surprisingly, PspA(145-222) effects changed completely in the presence of full-length PspA, as promoter activity was triggered instead of being inhibited under this condition. PspA(145-222) thus interfered with the inhibito

SUBMITTER: Heidrich ES 

PROVIDER: S-EPMC6003685 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature